The present invention concerns an actuator arrangement for a motor vehicle drive train which comprises at least one friction clutch for transmission of a drive torque, in particular in the form of a starting clutch, and a gear mechanism with at least two gears which can be engaged and disengaged by means of a shift clutch arrangement, with a hydraulic circuit having a pump which can be driven by means of an electric motor and having a clutch hydraulic cylinder, by means of which the friction clutch can be actuated, and with a shift actuator device for activating the shift clutch arrangement.
In the field of motor vehicle drive trains, automated gear mechanisms are known such as automated manual gear mechanisms, double clutch gear mechanisms, convertor automatic gear mechanisms etc. Automated gear mechanisms are fitted with suitable actuators both with regard to the clutch actuation and with regard to the shift actuation, so that these processes can proceed automatically.
To actuate the friction clutch, it is known and preferred to use hydraulic actuators, wherein the friction clutch is actuated by means of a clutch hydraulic cylinder. This allows a sensitive and rapid regulation of the torque transmitted via the friction clutch, which is important in particular in double clutch gear mechanisms. This is because here, two friction clutches are actuated in an overlapping manner for torque transmission from one power transmission branch to the other power transmission branch.
It is also known to use hydraulic cylinders as a shift actuator device to actuate individual shift clutch packages such as synchronization mechanisms. The advantage here is that a single fluid source can be used to actuate the friction clutch and to actuate the shift clutch.
It is however also known to actuate the shift clutch arrangement electrically, for example by electromagnetic actuators or electric motors. In the latter case, it is known to use so-called shift drums to actuate shift clutches, which are driven by means of an electric motor.
It is also known to provide shift clutch arrangements with selector shafts which are moved in the shift direction by means of a hydraulic cylinder and in the selection direction by means of an electric motor.
To regulate the pressure of a hydraulic fluid, it is known to use a pump to generate a line pressure which is held constant by means of a pressure-control valve. The pressures of individual hydraulic cylinders are then regulated using further pressure-control valves. It is known to couple the pumps to the internal combustion engine in the manner of an ancillary drive.
It is however also known to connect the pressure port of a pump directly to a hydraulic cylinder and drive the pump by means of an electric motor. In this case, it is also possible to regulate the pressure in the hydraulic cylinder by adjusting the rotation speed of the electric motor.